package org.apache.commons.jcs.auxiliary.lateral.socket.tcp;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.InetSocketAddress;
import java.net.Socket;
import org.apache.commons.jcs.auxiliary.lateral.LateralElementDescriptor;
import org.apache.commons.jcs.auxiliary.lateral.socket.tcp.behavior.ITCPLateralCacheAttributes;
import org.apache.commons.jcs.io.ObjectInputStreamClassLoaderAware;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* This class is based on the log4j SocketAppender class. I'm using a different repair structure, so
* it is significantly different.
*/
public class LateralTCPSender
{
/** The logger */
private static final Log log = LogFactory.getLog( LateralTCPSender.class );
/** Config */
private int socketOpenTimeOut;
private int socketSoTimeOut;
/** The stream from the server connection. */
private ObjectOutputStream oos;
/** The socket connection with the server. */
private Socket socket;
/** how many messages sent */
private int sendCnt = 0;
/** Use to synchronize multiple threads that may be trying to get. */
private final Object getLock = new int[0];
/**
* Constructor for the LateralTCPSender object.
* <p>
* @param lca
* @throws IOException
*/
public LateralTCPSender( ITCPLateralCacheAttributes lca )
throws IOException
{
this.socketOpenTimeOut = lca.getOpenTimeOut();
this.socketSoTimeOut = lca.getSocketTimeOut();
String p1 = lca.getTcpServer();
if ( p1 == null )
{
throw new IOException( "Invalid server (null)" );
}
String h2 = p1.substring( 0, p1.indexOf( ":" ) );
int po = Integer.parseInt( p1.substring( p1.indexOf( ":" ) + 1 ) );
if ( log.isDebugEnabled() )
{
log.debug( "h2 = " + h2 );
log.debug( "po = " + po );
}
if ( h2.length() == 0 )
{
throw new IOException( "Cannot connect to invalid address [" + h2 + ":" + po + "]" );
}
init( h2, po );
}
/**
* Creates a connection to a TCP server.
* <p>
* @param host
* @param port
* @throws IOException
*/
protected void init( String host, int port )
throws IOException
{
try
{
if ( log.isInfoEnabled() )
{
log.info( "Attempting connection to [" + host + "]" );
}
// have time out socket open do this for us
try
{
socket = new Socket();
socket.connect( new InetSocketAddress( host, port ), this.socketOpenTimeOut );
}
catch ( IOException ioe )
{
if (socket != null)
{
socket.close();
}
throw new IOException( "Cannot connect to " + host + ":" + port, ioe );
}
socket.setSoTimeout( socketSoTimeOut );
synchronized ( this )
{
oos = new ObjectOutputStream( socket.getOutputStream() );
}
}
catch ( java.net.ConnectException e )
{
log.debug( "Remote host [" + host + "] refused connection." );
throw e;
}
catch ( IOException e )
{
log.debug( "Could not connect to [" + host + "]. Exception is " + e );
throw e;
}
}
/**
* Sends commands to the lateral cache listener.
* <p>
* @param led
* @throws IOException
*/
public <K, V> void send( LateralElementDescriptor<K, V> led )
throws IOException
{
sendCnt++;
if ( log.isInfoEnabled() && sendCnt % 100 == 0 )
{
log.info( "Send Count (port " + socket.getPort() + ") = " + sendCnt );
}
if ( log.isDebugEnabled() )
{
log.debug( "sending LateralElementDescriptor" );
}
if ( led == null )
{
return;
}
if ( oos == null )
{
throw new IOException( "No remote connection is available for LateralTCPSender." );
}
synchronized ( this.getLock )
{
oos.writeUnshared( led );
oos.flush();
}
}
/**
* Sends commands to the lateral cache listener and gets a response. I'm afraid that we could
* get into a pretty bad blocking situation here. This needs work. I just wanted to get some
* form of get working. However, get is not recommended for performance reasons. If you have 10
* laterals, then you have to make 10 failed gets to find out none of the caches have the item.
* <p>
* @param led
* @return ICacheElement
* @throws IOException
*/
public <K, V> Object sendAndReceive( LateralElementDescriptor<K, V> led )
throws IOException
{
if ( led == null )
{
return null;
}
if ( oos == null )
{
throw new IOException( "No remote connection is available for LateralTCPSender." );
}
Object response = null;
// Synchronized to insure that the get requests to server from this
// sender and the responses are processed in order, else you could
// return the wrong item from the cache.
// This is a big block of code. May need to re-think this strategy.
// This may not be necessary.
// Normal puts, etc to laterals do not have to be synchronized.
synchronized ( this.getLock )
{
try
{
// clean up input stream, nothing should be there yet.
if ( socket.getInputStream().available() > 0 )
{
socket.getInputStream().read( new byte[socket.getInputStream().available()] );
}
}
catch ( IOException ioe )
{
log.error( "Problem cleaning socket before send " + socket, ioe );
throw ioe;
}
// write object to listener
oos.writeUnshared( led );
oos.flush();
ObjectInputStream ois = null;
try
{
socket.setSoTimeout( socketSoTimeOut );
ois = new ObjectInputStreamClassLoaderAware( socket.getInputStream(), null );
response = ois.readObject();
}
catch ( IOException ioe )
{
String message = "Could not open ObjectInputStream to " + socket +
" SoTimeout [" + socket.getSoTimeout() +
"] Connected [" + socket.isConnected() + "]";
log.error( message, ioe );
throw ioe;
}
catch ( Exception e )
{
log.error( e );
}
finally
{
if (ois != null)
{
ois.close();
}
}
}
return response;
}
/**
* Closes connection used by all LateralTCPSenders for this lateral connection. Dispose request
* should come into the facade and be sent to all lateral cache services. The lateral cache
* service will then call this method.
* <p>
* @throws IOException
*/
public void dispose()
throws IOException
{
if ( log.isInfoEnabled() )
{
log.info( "Dispose called" );
}
// WILL CLOSE CONNECTION USED BY ALL
oos.close();
socket.close();
}
}